biostudies-literatureEvans JPNational Center for Advancing Translational SciencesNICHD NIH HHSNCATS NIH HHSNIAID NIH HHSNHLBI NIH HHSNCI NIH HHSNational Institutes of Health1093-1102.e3https://www.ebi.ac.uk/biostudies/studies/S-EPMC9035359biostudies-literatureUnknown30(8)Recent reports of SARS-CoV-2 Omicron variant sub-lineages, BA.1, BA.1.1, and BA.2, have reignited concern over potential escape from vaccine- and infection-induced immunity. We examine the sensitivity of these sub-lineages and other major variants to neutralizing antibodies from mRNA-vaccinated and boosted individuals, as well as recovered COVID-19 patients, including those infected with Omicron. We find that all Omicron sub-lineages, especially BA.1 and BA.1.1, exhibit substantial immune escape that is largely overcome by mRNA vaccine booster doses. While Omicron BA.1.1 escapes almost completely from neutralization by early-pandemic COVID-19 patient sera and to a lesser extent from sera of Delta-infected patients, BA.1.1 is sensitive to Omicron-infected patient sera. Critically, all OmicrCell host & microbeNeutralization of SARS-CoV-2 Omicron sub-lineages BA.1, BA.1.1, and BA.2.PMC9035359R01 HD095881UL1 TR002733U54 CA260582R01 HL096376R01 AI150473KL2 TR002734Xu KFaraone JEvans JPMallampalli RGumina RJZhou TMohler PJZheng YMLiu SLZeng CQu PSaif LJLozanski GCarlin COltz EMBednash JSfalseNeutralization of SARS-CoV-2 Omicron sub-lineages BA.1, BA.1.1, and BA.2.Recent reports of SARS-CoV-2 Omicron variant sub-lineages, BA.1, BA.1.1, and BA.2, have reignited concern over potential escape from vaccine- and infection-induced immunity. We examine the sensitivity of these sub-lineages and other major variants to neutralizing antibodies from mRNA-vaccinated and boosted individuals, as well as recovered COVID-19 patients, including those infected with Omicron. We find that all Omicron sub-lineages, especially BA.1 and BA.1.1, exhibit substantial immune escape that is largely overcome by mRNA vaccine booster doses. While Omicron BA.1.1 escapes almost completely from neutralization by early-pandemic COVID-19 patient sera and to a lesser extent from sera of Delta-infected patients, BA.1.1 is sensitive to Omicron-infected patient sera. Critically, all Omicr2022-01-01T00:00:00Z2022 Aug2026-05-31T21:00:19.235Z2025-02-19T04:21:16.569ZS-EPMC90353593552653410.1016/j.chom.2022.04.014